The influence of X-ray irradiation on elastic, dynamical and structural characteristics of strained LiF crystals
The influence of a preliminary deformation ε = 0.4% and X-ray irradiation to exposure doses of 400 and 800 R
 on the frequency dependence of the sound velocity v(f) in LiF crystals in the frequency interval 37.5…172.5 MHz
 and at room temperature has been studied using the pulsed tec...
Saved in:
| Published in: | Вопросы атомной науки и техники |
|---|---|
| Date: | 2018 |
| Main Authors: | , , |
| Format: | Article |
| Language: | English |
| Published: |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2018
|
| Subjects: | |
| Online Access: | https://nasplib.isofts.kiev.ua/handle/123456789/147032 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Journal Title: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Cite this: | The influence of X-ray irradiation on elastic, dynamical and structural characteristics of strained LiF crystals / О.M. Petchenko, G.О. Petchenko, S.M. Boiko // Вопросы атомной науки и техники. — 2018. — № 2. — С. 25-28. — Бібліогр.: 14 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860258666163208192 |
|---|---|
| author | Petchenko, О.M. Petchenko, G.О. Boiko, S.M. |
| author_facet | Petchenko, О.M. Petchenko, G.О. Boiko, S.M. |
| citation_txt | The influence of X-ray irradiation on elastic, dynamical and structural characteristics of strained LiF crystals / О.M. Petchenko, G.О. Petchenko, S.M. Boiko // Вопросы атомной науки и техники. — 2018. — № 2. — С. 25-28. — Бібліогр.: 14 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | The influence of a preliminary deformation ε = 0.4% and X-ray irradiation to exposure doses of 400 and 800 R
on the frequency dependence of the sound velocity v(f) in LiF crystals in the frequency interval 37.5…172.5 MHz
and at room temperature has been studied using the pulsed technique. The coefficient of dynamic viscosity B and the
dislocation density Λ were found to be independent of the irradiation dose. The absolute values of B were found to
be lower and the values of Λ higher by an order of magnitude than the corresponding values obtained with the use of
the most reliable techniques, such as the methods of high-frequency internal friction and etch pit counting respectively.
Iмпульсним методом в областi частот 37,5…172,5 МГц при T = 300 К дослiджено вплив попередньої деформацiї ε = 0,4% i рентгенівського опромiнення дозами 400 та 800 Р на хiд частотних залежностей швидкостi ультразвуку v(f ) у кристалах LiF. Встановлено, що коефiцiєнт динамiчної в’язкостi В i густина дислокацiй Λ зi зростанням дози опромiнення залишаються незмiнними. Виявлено, що абсолютне значення величини В є в 10 разiв меншим, а величини Λ – у стiльки ж разiв бiльшим вiд тих значень, що дають найбiльш
коректнi методи високочастотного внутрiшнього тертя i прямого пiдрахунку ямок протравлювання
вiдповiдно.
Импульсным методом в области частот 37,5…172,5 МГц при T = 300 К исследованы влияния предварительной деформации ε = 0,4% и рентгеновского облучения дозами 400 и 800 Р на ход частотных зависимостей скорости ультразвука v(f) в кристаллах LiF. Установлено, что коэффициент динамической вязкости В и
плотность дислокаций Λ с увеличением дозы облучения остаются неизменными. Выявлено, что абсолютное
значение величины В в 10 раз меньше, а величины Λ – во столько же раз больше значений, которые дают
наиболее корректные методы: высокочастотного внутреннего трения и прямого подсчета ямок травления
соответственно.
|
| first_indexed | 2025-12-07T18:52:42Z |
| format | Article |
| fulltext |
ISSN 1562-6016. PASТ. 2018. №2(114), p. 25-28.
UDC 539.67:539.374
THE INFLUENCE OF X-RAY IRRADIATION ON ELASTIC,
DYNAMICAL AND STRUCTURAL CHARACTERISTICS OF STRAINED
LiF CRYSTALS
О.M. Petchenko
1
, G.О. Petchenko
1
, S.M. Boiko
2
1
O.M. Beketov Kharkiv National University of Urban Economy, Kharkоv, Ukraine
E-mail: gdaeron@ukr.net;
2
M.Ye. Zhukovskiy Kharkiv National Aerospace University, Kharkоv, Ukraine
E-mail: svitlanazagreba7@gmail.com
The influence of a preliminary deformation = 0.4% and X-ray irradiation to exposure doses of 400 and 800 R
on the frequency dependence of the sound velocity v(f) in LiF crystals in the frequency interval 37.5…172.5 MHz
and at room temperature has been studied using the pulsed technique. The coefficient of dynamic viscosity B and the
dislocation density Λ were found to be independent of the irradiation dose. The absolute values of B were found to
be lower and the values of Λ higher by an order of magnitude than the corresponding values obtained with the use of
the most reliable techniques, such as the methods of high-frequency internal friction and etch pit counting respec-
tively.
INTRODUCTION
It is greatly important to investigate the processes
that lead to the fixation of high-level dislocations with
the help of detected defects caused by radiation and the
determination of their influence on the frequency de-
pendence of the ultrasonic velocity, v(f). First, they give
us the opportunity to obtain data on the elastic proper-
ties of crystals reflecting the nature of the interparticle
bonds [1]; and secondly, they open the possibilities of
studying the nature of the interaction between disloca-
tions and elementary excitations in the crystal [2]. We
can't help saying that the experimental dependences v(f)
were earlier analyzed only for NaCl [3, 4] and LiF [5, 6]
crystals. The acoustic method used in works [3–6]
turned out rather informative. According to the disloca-
tion theory [7], this method can be used to determine the
key parameters of a dislocation structure, such as the
dislocation density Λ and the average effective length of
a dislocation segment L, provided that the constant of
dynamic dislocation damping B is known. The effect of
inverse shift for the dispersion curves v(f) was revealed
for the first time, and it is as follows the frequency
curves, when the residual deformation of the specimen
increases, first shift aligned towards low frequencies
and, after the X-ray irradiation of the specimen, it starts
to move in the opposite direction. In addition, having
determined the value of Λe by counting the etch pits, the
author of work [4–6] reasonably proves that the constant
of dislocation damping B does not depend on the dislo-
cation density. At the same time, it was marked that the
absolute value of B is considerably underestimated in
comparison with the value of Be determined in work [8]
using the conventional “reference” technique of high-
frequency internal friction, i. e. from the descending
branch in the frequency dependence of the dislocation
decrement Δd(f) for the crystals of the same batch. In the
recent works [5, 6], our main goals were the verifying of
the presence of effects observed in work [4] and the
fitting of the results obtained by the cited authors for
other crystals, in particular, LiF. For this purpose, the
frequency dependences of ultrasonic velocity in crystals
were investigated using non-strained specimens, speci-
mens strained to ε = 0.65%, and strained specimens
irradiated to 800 R. Along with the results of works [3,
4], the deformation gave rise to a shift of the v(f) curve
toward low frequencies, whereas irradiation, as was
observed in work [4], resulted in the inverse shift of this
curve. Moreover LiF specimens, similarly to NaCl ones
[4], demonstrate a tendency for the parameters B and Λ
to be independent of the irradiation dose. In work [5, 6],
a reduction of the average effective length of a disloca-
tion segment L under the action of irradiation was also
registered. This fact is in good qualitative agreement
with the results of works [8, 9], where the specimens of
the same batch were used to study the structural charac-
teristics of crystals (from the high-frequency asymptote
of the above-mentioned resonance curve Δd(f)). Based
on all of the foregoing, we continue, in this work, the
researches started in work [5, 6] devoted to the influ-
ence of X-ray irradiation on the dispersion dependences
v(f) in LiF crystals.
MATERIALS
AND EXPERIMENTAL TECHNIQUES
This study addresses an important issue the influ-
ence of long-wave X-ray radiation of low doses on the
frequency dependence of the elastic wave velocity, v(f),
in the frequency interval of 37.5…172.5 MHz in LiF
crystals with the residual strain = 0.4% and at
T = 300 K. The selector method, as sufficiently effec-
tive, was chosen by the authors to measure the velocity
of the propagation of ultrasonic waves, and also the
installation described in [5, 6] was used. The specimens
with a purity of 10
-4
wt.%, with the crystallographic
orientation <100>, and 17х17х29 mm in dimension we
used carrying out the experiments. According to the
technology described in works [4–6, 8, 9], the speci-
mens to study, after their cutoff, were finely polished to
achieve the non-parallelism of working surfaces of ap-
proximately 1 m/cm, which was controlled by means
of an IKV optimeter. The surface non-parallelism in the
system “piezoquartz–sticker–specimen” could also be
estimated independently when imposing the exponential
reference signal on a series of reflected pulses observed
mailto:gdaeron@ukr.net
mailto:svitlanazagreba7@gmail.com
on the oscilloscope screen in the course of crystal
sounding. To remove the internal stresses that could
emerge owing to a mechanical treatment of the speci-
mens, the latter were annealed in a muffle furnace
MP-2UM for 12 h at a temperature of about 0.8 Tmelt
and, then, slowly cooled down to room temperature. For
highly mobile dislocations to be introduced into the
crystal, the latter was preliminarily deformed to achieve
the residual strain = 0.4%. At the indicated values of
experimental parameters, the dispersion curve v(f) had
such initial frequency position, from which it was con-
venient to observe its further shift toward high frequen-
cies in the course of dislocation fixation by radiation-
induced defects. The achievement of the required resid-
ual deformation was checked up by means of the exact
registration of the crystal yield point on a tape recorder
KSP-4. The working length of the crystal before and
after deformation was monitored to an accuracy of 1 m
with the help of a comparator IZA-2. The specimens
were deformed by squeezing them on an Instron ma-
chine at a rate of about 10
-5
s
-1
. In this regime of defor-
mation [4–6, 8, 9], no slip bands arise, and the etch pits
regularly cover the crystal surface, which enables the
dislocation density Λe to be accurately determined with
the use of the software Photoshop. The procedure of
specimen irradiation with X-rays did not differ from that
described in works [5, 6].
RESULTS AND DISCUSSION
Fig. 1 shows that the experimental dependences v(f)
shown for the LiF crystals are not intense (curve 1) [5,
6] and are deformed and irradiated later with X-rays of
400 and 800 R (curves 2, 3). It can be seen that the na-
ture of the frequency dependences v(f) varies signifi-
cantly when the dislocation structure of the crystal pass-
es from one state to another. Initially, when “growing”
dislocations are fixed by the impurity atoms in a non-
deformed (annealed) crystal, the propagation velocity of
acoustic waves practically linearly changes when the
frequency increased (curve 1).
Fig. 1. Frequency dependences of the ultrasonic propa-
gation velocity in LiF crystals where (1) a non-strained
and non-irradiated specimen, (2, 3) a specimens with a
residual deformation of 0.4%, and X-ray – irradiated to
400 and 800 R, respectively
Then, with the appearance of a significant number of
highly mobile dislocations in the crystal owing to its
deformation to 0.4% the frequency dependence v(f)
emerged a pronounced interval with dispersion, which is
especially notable in the low-frequency section. The
X-irradiation of specimen to doses 400 and 800 R
approached the frequency dependences v(f) (curves 2, 3)
to the frequency position of curve 1 for the non-
deformed specimen. The results presented in Fig. 1 can
be interpreted in accordance with [7] in the following
way. At low frequencies, the dislocation moves in an
overlapping phase, and the actual hardness of the crys-
tals is lower than that of non-dislocation. When the fre-
quency increases, the synchronism between the disloca-
tion moves and the excited external field is substantially
violated, and the modulus of elasticity reaches its true
value. After the set of dispersion curves v(f) had been
obtained, we plotted the corresponding dependences of
the modulus defect ΔC11/C11 on the frequency f (Fig. 2).
We note that the modulus defect was calculated in this
work using the equation 2ΔV/V∞ = ΔC11/C11, where
ΔV = V∞–V. The purely elastic velocity
V∞ = 6.6110
3
m/s was measured at a frequency of
217.5 MHz (see Fig.1, curve 1), when the crystal be-
haves itself as an ideal one owing to the absence of dis-
location effects.
Fig. 2. Frequency dependences of the modulus defect in
LiF crystals deformed to 0.4%, and X-ray-irradiated to
400 (2) and 800 R (1) respectively. Solid curves are the
theoretical curves taken from work [10]
The Fig. 2 demonstrates that the experimental curves
(1, 2) decrease by amplitude and are shifted toward
higher frequencies with the increase of X-irradiation
dose. The array of experimental points in Fig. 2 was
approximated by the frequency dependence of the mod-
ulus defect calculated in work [10] for the function
(ΔC11/C11)(f) in the approximation, when the dislocation
segments are distributed exponentially over their
lengths. One can see that the experimental and theoreti-
cal data are in satisfactory agreement with one another.
Imposing the theoretical profile on the experimental
data made it possible to determine its frequency and
amplitude positions, which allowed us to determine, in a
well-founded manner and directly from the theoretical
curve, the values of the frequency, f0, and the modulus
defect, (ΔC11/C11)0, corresponding to the points of the
curves in Fig. 2, where their linear behavior terminated
[5, 6]. These are those “reference” points, where the
modulus defect (ΔC11/C11)0 extrapolated to the low-
frequency region starts to acquire its maximum value.
It should be noted that the absolute values of ultra-
sound velocity in the frequency interval
37.5…172.5 MHz were measured to an accuracy of
0.05…0.1% [6], whereas the modulus defect
(ΔC11/C11)0 and the frequency were determined from the
0 50 100 150 200 250
6,5
6,6
6,5
6,6
6,5
6,6
6,5
6,6
0 50 100 150 200 250
6,5
6,6
0 50 100 150 200 250
6,5
6,6
1 - 0 R
2 - 400 R
3 - 800 R
3
2
1
LiF
0,4%
V
,1
0
3
m
/s
f,MHz
10 100
0,01
0,1
C
1
1
/
C
1
1
1
10 100
0,01
0,1
10 100
0,01
0,1
2
10 100
0,01
0,1
10 100
0,01
0,1
10 100
0,01
0,1
f, MHz10 100
0,01
0,1
10 100
0,01
0,1
10 100
0,01
0,1
10 100
0,01
0,1
1 - 800 R
2 - 400 R
LiF 0,4 %
0.4%
LiF 0.4%
data (see Fig. 2) with an accuracy of 5…7 or 15…20%,
respectively. On the basis of experimental results de-
picted in Fig. 2 and using the theoretical relations de-
scribing the low-frequency branch of the dislocation
resonance [7], it is possible to calculate the coefficient
of dislocation damping B and to determine the main
parameters of the crystal dislocation structure, Λ and L.
According to the theory [7], the formula for the modulus
defect extrapolated to the low-frequency region looks
like:
2
0
11
6
.11
Ω Δ Λ LΔC
=
C π
(1)
Substituting the expressions
2
3
8
0
G b
Δ =
π C
,
2
0
0.084
2 m
π C
L =
B f
, taken from work [7] into Eq. (1),
we obtain a relation for the calculation of Λ in the form:
3 0
02
11
,
2.016
m e 11
π f B ΔC
Λ= ( )
Ω G b C
(2)
where Ω is the orientation factor; G the shear modulus;
b the magnitude of Burgers vector; (ΔC11/C11)0 the value
of modulus defect measured at the frequency f0, and Be
the constant of dislocation damping. Carrying out the
calculations by formula (2), in which we take Ω = 0.311
and G∙b
2
= 28.7710
-10
Pa/m
2
[9], and the damping con-
stant Be = 3.6210
-5
Pas obtained recently for the re-
searched crystals in work [9], we obtain the
Λ = 1.4410
11
m
-2
(400 R) and Λ = 1.510
11
m
-2
(800 R).
The invariance of the dislocation density Λ observed
experimentally at various exposure doses of irradiation
is quite expectable, because the doses applied in our
experiments were negligibly low in comparison with
those that could stimulate a crystal deformation [11]. At
the same time, the average value 1.4710
11
m
-2
calculat-
ed by formula (2) raises some doubts, because it is by an
order of magnitude larger that the corresponding value
Λe = 1.4510
11
m
-2
found directly by counting the etch
pits on the crystal surface [9]. After the base of experi-
mental data had been created, the calculation of another
parameter of the dislocation structure, L, in the frame-
work of the theory [7] became possible by the formula:
2
0
0.084
1e m
G b
L =
B f ( υ)
, (3)
where is Poisson’s ratio. Substituting = 0.27 [5, 6]
into formula (3), we calculated L. As was expected, an
increase of the exposure dose gives rise to a monotonic
decrease of the effective length of a dislocation seg-
ment, L, from L = 9.98∙10
-7
m (400 R) to 7.81∙10
-7
m
(800 R) owing to its fixation by radiation-induced de-
fects. However, the initial value of L obtained before the
irradiation was approximately 2, 3 times larger than the
value determined in work [8] on the basis of equations
describing the position of the dislocation resonance. By
solving Eq. (2), we obtain the following expression for
the coefficient of dislocation damping:
2
0 3
0
11
2.016 e
11
m
Ω G b Λ
B =
ΔС
f ( ) π
С
. (4)
The results of calculations by this formula show that
the damping coefficient B for LiF crystals, similarly to
what was obtained in works [8, 9], does not depend on
the irradiation dose (3.610
-6
Pas). However, the abso-
lute value of the constant B turned out by an order of
magnitude smaller than the value of Be determined using
the method of high-frequency internal friction [8, 9] by
analyzing the descending branch of the dislocation res-
onance. The determined results agrees with the theoreti-
cal conclusions [2] that the dynamic dislocation damp-
ing at a constant temperature is governed only by
dissipative processes in the phonon subsystem of the
crystal. From the analysis of experimental data, it fol-
lows that the obtained results concerning the revealed
independence of the quantities B and Λ of the irradiation
dose and a decrease of the dislocation mobility, which
reveals itself in a reduction of L with the growth of the
irradiation dose, qualitatively coincide with the data
obtained, by using the well-known methods of research-
es mentioned above [9, 12, 13]. However, there exists a
considerable quantitative discrepancy between the val-
ues determined in this work and those obtained in work
[8]; this is especially true for the absolute estimates of
the quantities B and Λ. Those data confirm the conclu-
sion made by the authors of work [14] that it is impossi-
ble to describe experimental data for the indicated fre-
quency ranges in the framework of the theory [7], by
engaging only a unique mechanism of ultrasound ab-
sorption. In accordance with work [14], the results of
measurements can be described by a general frequency
profile only if different B values are used for every fre-
quency branch.
CONCLUSIONS
The effect of long-wave X-ray irradiation in small
doses on the dispersion of ultrasound velocity, v(f), in
LiF crystals with a residual deformation of 0.4%, was
studied in the frequency range from 37.5 to 172.5 MHz
and at T = 300 K. Preliminary deformation of the sam-
ples was found to result in a pronounced dispersion re-
gion on the v(f) curve, which was linear in undeformed
samples. It was found that the phenomenon of scattering
is especially noticeable at low frequencies, when the
scattering of the elastic energy of ultrasonic waves is
due to the high mobility of long dislocation loops. It is
established that the dislocation damping is constant B
and the dislocation density Λ remains unchanged with
increasing radiation dose. An analysis of the results
shows that the absolute value of B is less, and the value
of Λ is greater by an order of magnitude than the corre-
sponding values of Be and Λe obtained in the framework
of the usual methods of high-frequency internal friction
and selective etching of the surface of the crystal, re-
spectively.
REFERENCES
1. S.P. Nikanorov, B.K. Kardashov. Elasticity and
Dislocation Inelasticity of Crystals. M.: “Nauka”, 1985,
256 р.
2. V.I. Alshits, V.L. Indenbom. Dynamic drag of
dislocations // Usp. Fiz. Nauk. 1975, v. 115, N 3,
p. 3-39 (in Russian).
3. A. Granato, J. De Klerk, R. Truell. Dispersion of
elastic waves in sodium chloride // Phys. Rev. 1957,
v. 108, N 3, p. 895-896.
4. A.M. Petchenko. Dispersion of the velocity of
longitudinal ultrasonic waves in LiF crystals // Fiz.
Tverd. Tela. 1990, v. 2, N 11, p. 3362-3365 (in Rus-
sian).
5. G.A. Petchenko. Dispersion of elastic waves in
LiF crystals // Visn. Kharkiv. Nats. Univ. 2012, v. 17,
N 1020, p. 83-86 (in Ukrainian).
6. G.O. Petchenko, О.M. Petchenko. Research of
the elastic wave velocity dispersion in X-ray-irradiated
LiF crystals // Ukrainian Journal of Physics. 2013,
v. 58, N 10, p. 974-979.
7. А. Granato, K. Lücke. String model of
dislocation and dislocation ultrasound absorption //
Physical Acoustic. М.: “Mir”, 1969, v. 4, part А, p. 261-
321.
8. G.A. Petchenko. The investigation of the disloca-
tions resonance losses of ultrasonic sound in irradiated
LiF single crystals in the interval of irradiation doses
0…400 R // Problems of Atomic Science and Technolo-
gy. Series “Physics of Radiation Effect and Radiation
Materials Science”. 2012, v. 78, N 2(78), p. 36-39.
9. G.A. Petchenko. Research of the preliminary de-
formation and irradiation effect on the viscous damping
of dislocation in LiF crystals // Functional Materials.
2013, v. 20, N 3, p. 315-320.
10. O.S. Oen, D.K. Holmes, and M.T. Robinson. US
AEC Report ORNL-3017. 1960, N 3.
11. A.A. Botaki, A.A. Vorob’ev, B.L. Ulyanov. Ra-
diation Physics of Ionic Crystals. M.: “Atomizdat”,
1980, 208 р.
12. G.O. Petchenko. Acoustic studies of the effect of
X-ray irradiation on the dynamic drag of dislocations in
LiF crystals // Ukrainian Journal of Physics. 2011,
v. 56, N 4, p. 339-343.
13. A.M. Petchenko, G.A. Petchenko. Dynamic
damping of dislocations with phonons in KBr single
crystals // Functional Materials. 2006, v. 13, N 3,
p. 403-405.
14. V. Naundorf, K. Lücke. Mechanisms of Internal
Friction in Solids. M.: “Nauka”, 1976, 91 p.
Article received 22.12.2017
ВЛИЯНИЕ РЕНТГЕНОВСКОГО ОБЛУЧЕНИЯ НА УПРУГИЕ, ДИНАМИЧЕСКИЕ
И СТРУКТУРНЫЕ ХАРАКТЕРИСТИКИ ПРОДЕФОРМОВАННЫХ КРИСТАЛЛОВ LiF
А.М. Петченко, Г.А. Петченко, С.Н. Бойко
Импульсным методом в области частот 37,5…172,5 МГц при T = 300 К исследованы влияния предвари-
тельной деформации = 0,4% и рентгеновского облучения дозами 400 и 800 Р на ход частотных зависимо-
стей скорости ультразвука v(f) в кристаллах LiF. Установлено, что коэффициент динамической вязкости В и
плотность дислокаций Λ с увеличением дозы облучения остаются неизменными. Выявлено, что абсолютное
значение величины В в 10 раз меньше, а величины Λ – во столько же раз больше значений, которые дают
наиболее корректные методы: высокочастотного внутреннего трения и прямого подсчета ямок травления
соответственно.
ВПЛИВ РЕНТГЕНІВСЬКОГО ОПРОМІНЕННЯ НА ПРУЖНІ, ДИНАМІЧНІ
І СТРУКТУРНІ ХАРАКТЕРИСТИКИ ПРОДЕФОРМОВАНИХ КРИСТАЛІВ LiF
О.М. Петченко, Г.О. Петченко, С.М. Бойко
Iмпульсним методом в областi частот 37,5…172,5 МГц при T = 300 К дослiджено вплив попередньої де-
формацiї = 0,4% i рентгенівського опромiнення дозами 400 та 800 Р на хiд частотних залежностей швид-
костi ультразвуку v(f ) у кристалах LiF. Встановлено, що коефiцiєнт динамiчної в’язкостi В i густина дисло-
кацiй Λ зi зростанням дози опромiнення залишаються незмiнними. Виявлено, що абсолютне значення вели-
чини В є в 10 разiв меншим, а величини Λ – у стiльки ж разiв бiльшим вiд тих значень, що дають найбiльш
коректнi методи високочастотного внутрiшнього тертя i прямого пiдрахунку ямок протравлювання
вiдповiдно.
|
| id | nasplib_isofts_kiev_ua-123456789-147032 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-07T18:52:42Z |
| publishDate | 2018 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Petchenko, О.M. Petchenko, G.О. Boiko, S.M. 2019-02-13T11:42:06Z 2019-02-13T11:42:06Z 2018 The influence of X-ray irradiation on elastic, dynamical and structural characteristics of strained LiF crystals / О.M. Petchenko, G.О. Petchenko, S.M. Boiko // Вопросы атомной науки и техники. — 2018. — № 2. — С. 25-28. — Бібліогр.: 14 назв. — англ. 1562-6016 https://nasplib.isofts.kiev.ua/handle/123456789/147032 539.67:539.374 The influence of a preliminary deformation ε = 0.4% and X-ray irradiation to exposure doses of 400 and 800 R
 on the frequency dependence of the sound velocity v(f) in LiF crystals in the frequency interval 37.5…172.5 MHz
 and at room temperature has been studied using the pulsed technique. The coefficient of dynamic viscosity B and the
 dislocation density Λ were found to be independent of the irradiation dose. The absolute values of B were found to
 be lower and the values of Λ higher by an order of magnitude than the corresponding values obtained with the use of
 the most reliable techniques, such as the methods of high-frequency internal friction and etch pit counting respectively. Iмпульсним методом в областi частот 37,5…172,5 МГц при T = 300 К дослiджено вплив попередньої деформацiї ε = 0,4% i рентгенівського опромiнення дозами 400 та 800 Р на хiд частотних залежностей швидкостi ультразвуку v(f ) у кристалах LiF. Встановлено, що коефiцiєнт динамiчної в’язкостi В i густина дислокацiй Λ зi зростанням дози опромiнення залишаються незмiнними. Виявлено, що абсолютне значення величини В є в 10 разiв меншим, а величини Λ – у стiльки ж разiв бiльшим вiд тих значень, що дають найбiльш
 коректнi методи високочастотного внутрiшнього тертя i прямого пiдрахунку ямок протравлювання
 вiдповiдно. Импульсным методом в области частот 37,5…172,5 МГц при T = 300 К исследованы влияния предварительной деформации ε = 0,4% и рентгеновского облучения дозами 400 и 800 Р на ход частотных зависимостей скорости ультразвука v(f) в кристаллах LiF. Установлено, что коэффициент динамической вязкости В и
 плотность дислокаций Λ с увеличением дозы облучения остаются неизменными. Выявлено, что абсолютное
 значение величины В в 10 раз меньше, а величины Λ – во столько же раз больше значений, которые дают
 наиболее корректные методы: высокочастотного внутреннего трения и прямого подсчета ямок травления
 соответственно. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Физика радиационных повреждений и явлений в твердых телах The influence of X-ray irradiation on elastic, dynamical and structural characteristics of strained LiF crystals Вплив рентгенівського опромінення на пружні, динамічні і структурні характеристики продеформованих кристалів LiF Влияние рентгеновского облучения на упругие, динамические и структурные характеристики продеформированных кристаллов LiF Article published earlier |
| spellingShingle | The influence of X-ray irradiation on elastic, dynamical and structural characteristics of strained LiF crystals Petchenko, О.M. Petchenko, G.О. Boiko, S.M. Физика радиационных повреждений и явлений в твердых телах |
| title | The influence of X-ray irradiation on elastic, dynamical and structural characteristics of strained LiF crystals |
| title_alt | Вплив рентгенівського опромінення на пружні, динамічні і структурні характеристики продеформованих кристалів LiF Влияние рентгеновского облучения на упругие, динамические и структурные характеристики продеформированных кристаллов LiF |
| title_full | The influence of X-ray irradiation on elastic, dynamical and structural characteristics of strained LiF crystals |
| title_fullStr | The influence of X-ray irradiation on elastic, dynamical and structural characteristics of strained LiF crystals |
| title_full_unstemmed | The influence of X-ray irradiation on elastic, dynamical and structural characteristics of strained LiF crystals |
| title_short | The influence of X-ray irradiation on elastic, dynamical and structural characteristics of strained LiF crystals |
| title_sort | influence of x-ray irradiation on elastic, dynamical and structural characteristics of strained lif crystals |
| topic | Физика радиационных повреждений и явлений в твердых телах |
| topic_facet | Физика радиационных повреждений и явлений в твердых телах |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/147032 |
| work_keys_str_mv | AT petchenkoom theinfluenceofxrayirradiationonelasticdynamicalandstructuralcharacteristicsofstrainedlifcrystals AT petchenkogo theinfluenceofxrayirradiationonelasticdynamicalandstructuralcharacteristicsofstrainedlifcrystals AT boikosm theinfluenceofxrayirradiationonelasticdynamicalandstructuralcharacteristicsofstrainedlifcrystals AT petchenkoom vplivrentgenívsʹkogoopromínennânapružnídinamíčníístrukturníharakteristikiprodeformovanihkristalívlif AT petchenkogo vplivrentgenívsʹkogoopromínennânapružnídinamíčníístrukturníharakteristikiprodeformovanihkristalívlif AT boikosm vplivrentgenívsʹkogoopromínennânapružnídinamíčníístrukturníharakteristikiprodeformovanihkristalívlif AT petchenkoom vliânierentgenovskogooblučeniânauprugiedinamičeskieistrukturnyeharakteristikiprodeformirovannyhkristallovlif AT petchenkogo vliânierentgenovskogooblučeniânauprugiedinamičeskieistrukturnyeharakteristikiprodeformirovannyhkristallovlif AT boikosm vliânierentgenovskogooblučeniânauprugiedinamičeskieistrukturnyeharakteristikiprodeformirovannyhkristallovlif AT petchenkoom influenceofxrayirradiationonelasticdynamicalandstructuralcharacteristicsofstrainedlifcrystals AT petchenkogo influenceofxrayirradiationonelasticdynamicalandstructuralcharacteristicsofstrainedlifcrystals AT boikosm influenceofxrayirradiationonelasticdynamicalandstructuralcharacteristicsofstrainedlifcrystals |